High frequency electrical switch



April 25, 1939. 4 F] FRESE 2,155,537

HIGH FREQUENCY ELECTRICAL SWITCH DETAIL Original Filed Aug. 5, 1935INVENTOR.

PATENT OFFICE HIGH FREQUENCY ELECTRICAL SWITCH DETAIL Joseph F. Frese,Baltimore, Md.,, assignor to Monitor Controller Company, Baltimore, Md.,a corporation of Maryland Original application August 5, 1933, SerialNo.

5 Claims.

My invention relates broadly to electrical switches and moreparticularly to a construction of switch arm for use in high frequencyswitch systems.

This application is a division of my copending application Serial Number683,861, filed August 5, 1933, for High frequency electrical switch andcontactor system, now Patent Number 2,080,861, issued May 18, 1937.

One of the objects of my invention is to provide a construction ofelectrical switch arm offering minimum electrical capacity and subjectto minimum losses when employed in high frequency circuits.

Another object of my invention is to provide a construction of switcharm affording a broad contact area at the contact surfaces thereof, anda low-loss connection at the pivoted end thereof.

Still another object of my invention is to provide a switch armconstituted by a tubular conductor having a flattened portion at one endaffording contact mounting means, the tubular construction of the switcharm being particularly meritorious in high frequency electrical,

circuits.

A further object of my invention is to provide a switch arm constitutedby a tubular conductor adapted to be pivotally mounted adjacent one endthereof, and having a flexible connector secured at the pivoted endthereof for effecting a low-loss connection thereto.

Other and further objects of my invention reside in the construction andadaptation of the switch arm hereinafter more fully described withreference to the accompanying drawing in which:

Figure 1 is a side elevation of the switch arm of my invention; Fig. 2is a plan View of the same; Fig. 3 is a detailed vertical section takenadjacent the pivotal end of the switch arm and shows the flexibleconnector secured in the tubular switch arm; Fig. 4 is a cross-sectionalview taken on line 44 in Fig. 3; Fig. 5 is an end elevation of theswitch arm of my invention, looking in the direction of the line 5-5 inFig. 1; and Fig. 6 is a general view of the switch arm of my inventionas mounted for operation in a high frequency electrical switch.

The switch arm in a high frequency switch system is a critical unit. Theother elements of a high frequency electrical system may be more or lesseasily designed for eflicient operation at high frequencies, but theswitch arm, because of the mechanical considerations attending itsmounting and its actuation, presents particular problems affecting itsefficient operation in a high frequency electrical system. The tubularswitch arm of my invention is highly efficient in operation, carryinghigh frequency currents with minimum loss and capacity effects.

Divided and this application July 23, 1936, Serial No. 92,261

Referring to the drawing in more detail the switch arm of my inventioncomprises a tubular member 16, substantially elliptical incross-section, adapted to be pivotally mounted adjacent one end, andhaving contacts on the other end. I provide means intermediate thepivoted end and the end carrying the contacts for the connection ofactuating means to shift the switch arm to selected positions. Thetubular member I6 is provided at one end with a plug l8, as shownparticularly in Figs. 3 and 4, and an aperture I1 is formed in thetubular member l6 and the plug l8 to provide a journal for pivotallymounting the switch arm. The tubular member has a flexible connector I 9secured in positive contact therewith by means of the plug l8, as shownin Figs. 3 and 4. The flexible conductor is prevented from being pulledout by the knots shown, or other suitable enlargements on the conductorl9. or welded in place in order to secure the flexible conductorpermanently in place; or the plug may have only a force fit in thetubular member whereby it may be removed for replacement of the flexibleconductor.

The other end of the tubular member I6 is flattened in the direction ofthe major axis of the elliptical cross-section, forming flat faces inplanes parallel to the minor axis of the elliptical cross-section asshown at 2| in Figs. 1, 2 and 5, and contacts 22 are mounted thereon inany convenient manner. The form of switch arm shown is intended foroperation in a doublethrow switch system, such as shown in Fig. 6, andaccordingly two contacts are shown, one on each side of the flattenedportion ii. The broad faces of the flattened portion afford adequatespace for the mounting of contacts having large contact areas forreducing the contactlosses in the switch. I

As noted, the tubular member [6 is substantially elliptical incross-section, as shown particularly in Fig. 4, and the rigid mountingof the plug l8 therein is thus facilitated. Further-= more, the pivotalmounting of the switch arm at the aperture I1 is also improvedtherebyyas addition, the switch'arrn is apertured, as at 20,

between the ends and in the direction of the minor axis of theelliptical tubular member, to

The plug 18 may be brazedprovide a journal for the pivotal connection ofthrow, high frequency electrical switch assem-f bly, employing theswitch arm of my invention.

Reference character I designates the base on which the parts of the highfrequency switchwhich minimum dielectric losses'occur by reason of thearrangement of the contact and pivot fittings with respect to thestandards. It will be noted that all mechanical stresses on the'dielectrio standards are produced longitudinally of the standards sothatm'ec'hanical sheer stresses are "reduced toa minimum. The sockets 6are maintained in position with"'respect to base I by bolt members 1. aV

The dielectric standard 8 is mounted in one of the"'s'ocketsw5 andprovides a dielectric support for the pivot of the high frequency switcharm. The dielectric standard 9 is carried in the otherjof the socketsupports and provides a mounting means for stationary contactsengageable by'the contacts on the switch arm.

'A'fltting'lll is mountedon the extremity of the dielectric standard 8by means of bolt II. The fl'tting I0 supports the pivot pin I5 whichpasses through the aperture [1 in the tubular member l6. 4 The flexibleconductor I9 is held between the lug I2 and fitting l0 by'the bolt Hwhich extends into the lug l2. Conductor Hi, from the high frequencycircuit, forms a positive'connection'throughthe lug l2 and the flexibleconnector l9 with the tubular conductor I6, thereby avoiding the loss ofhigh frequency energy incident to connection through the pivotalmounting.

Stationary contact systems are mounted in V spaced, selectivelyoperative positions on the dielectric standard}. 7 eludes a contact 10'yieldably carried on anarm 66 and connected through a flexible conductorH. Lugs 5 1 and are connected tothefiexible conductors H, and to theirrespective circuits through'conductors 58- and' 60 respectively. Thecontacts 22 on either side of the flattened portion 2| of the arm [6 areadapted toengage either of'the contacts 10. The switch arm is pivotallyconnected with insulation member 24 by means of' pin 23 extendingthrough the aperture 20 in the tubular member I6. The insulationmember'24' constitutes actuating means and may be automatically or manuallyoperated. The apparatus shown connected-with the actuating member It ispart of" the automatiqmotor'op erated, switch control system forming thesubject matter of my copending 'ap'plication serial No, 683,861, supra,of which this application is a division.

The switch construction of my invention has been found highly practicalin production and efficient in operation, and while I have described myinvention in certain preferred em'-' bodiments, I desire th'atj'it beunderstoo'dfthat modificationsmay be made and that no limitations uponmy inventionare intended other than are imposed by the scope of theappended claims.

-Wha't I claim as new; and desire to secureby letters Patent ofthe'United States, is as 'fol The" I employ, a

Each contact system in-i ,1. In, a high frequency electrical switch, aswitch arm comprising a tubular conductor, a flexibleconnectorexte'nding within one end of said tubular conductor, a plugdisposed in said tubular conductor at the said end thereof and adaptedto secure said flexible connector in positive connection with saidtubular conductor, and .a contact on the other end of said switch arm,

said tubular conductor and said plug being apertured ior pivotallymounting said tubular conductor.

2; In a high frequency electrical switch, a switch arm comprising atubular conductor of substantially elliptical cross-section, the wallsof one end of said tubular conductor being flattened into intimatecontact on a line parallel to the minorax'is of the ellipticalcross-section of said tubular conductor, contacts mounted on the facesofthe flattened end of said conductorysaid conductor having aperturestherethrough' on'the minor axis of the elliptical cross-section thereof, one of's'aidapertures affording 'a pivotal mounting for said switcharm, and'the other of said apertures affording a connection foractuating means for said switch arm, anda flexible connector secured tosaid-tubular conductor for making positive electrical contact therewith.

3.111 a high frequency electrical switch, a movable switch arm forconducting high fre quency currents comprising a hollow tubularconductor having a large surface area for the distribution of highfrequency currents transmitted by said member, a braided flexible con-4. In an electrical switch, a switch arm'coi'n prising a tubularconductor of substantially elliptical cross-section, opposite sides ofsaid tubular conductor being flattened into contact with each other'atone 'endof" said conductor, a flexible connector looped and' having theend 'por nu s thereof disposed in the" opposite end of said conductorinthe recesses at opposite ends of the major axis-of the ellipticalcross-section of said conductor, a' plug having recesses for saidconnecto'r andshaped to fitwithin the open end of said'conductor betweenthe end portions of said connector, conductor and saidplug beingcentrally ape'rtured on the minor axis of the ellipticalcross-section ofsaid conductor, and a pin member mounted in the aperture for maintainingsaid" plug in'positi'on and pivotally' mounting said tubular conductorfor movement in the direction of themajor'axis of the substantiallyelliptical cross-section thereof.

5. In an electrical switch, a switch arm as set forth in'claim 4 whereinthe ends of said flexible connector are knotted within said tubularconductor for 'coaction with said plug'in securing said connector inposition.

JOSEPH F. FRESE.

